Page 66 - Speedhorse March 2018

WayS To Improve
STallIon Semen
QualITy & moTIlITy
Not all stallions are blessed with high fertility and high sperm counts, so it may take some extra effort to maxiize their ability to settle mares
by Heather Smith Thomas
There are many factors that can affect semen motil- ity in stallions according to Dr. Peter Sheerin, owner of Nandi Veterinary Associates in New Freedom, Pennsylvania. Stallion owners, however, can try to improve semen motility in several ways.
“There are some supplements that can be fed to increase the longevity and motility of sperm. The original product was called Magnitude and it’s made from fish oil and is high in omega-3 fatty acids.
Since that came out, it seems like everyone is trying to market an omega-3 product. This makes it harder for people to figure out which product they should use. The key is the omega-3 fatty acids. I would say that Magnitude may be the only product that has the research behind it. This doesn’t mean that the others won’t be helpful, but research always makes a product more credible,” says Sheerin.
Research was done with several stallions that
had been fed the product. “The researchers collected semen, extended it and checked it for motility prior to starting these stallions on the supplement. After those stallions had been on the supplement for more than 60 days, they collected and looked at the semen again and found that the motility was maintained for a longer period in the stallions that had been fed the product,” he says.
“This supplement will not make a good stallion better, but it will usually make a questionable stallion tolerable. Those questionable stallions might be able to settle more mares since the sperm motility will last longer and have the potential to increase pregnancy rates,” he explains. If a horse breeder has a stallion that is borderline and is working with that stallion
to try to improve fertility, this is a supplement that might be helpful.
“The thing they need to realize, however, is that they need to start the stallion on the supplement at least 60 days before the start of the breeding season. It takes that long for sperm to develop and go through the whole cycle.” Nutrition is a factor.
“The other big thing that can interfere with motil- ity is excess seminal plasma. Some stallions have a problem because seminal plasma is toxic to the sperm. Those stallions can benefit from their semen being centrifuged. The seminal fluid is spun off and dis- carded to get rid of the seminal plasma that is causing the problem,” says Sheerin.
“Typically, we see this situation in a stallion with a dilute ejaculate. There is a lot of seminal plasma and
Some supplements can be fed to increase the longevity and motility of sperm. The original product, called Magnitude, is made from fish oil and is high in omega-3 fatty acids.
just a little bit of sperm. There are also some horses that have a normal concentration of sperm, but the motility doesn’t last as long. These stallions would also benefit from being centrifuged,” he says.
Those are the two main ways to increase sperm motility, but other methods can also be tried. “Everyone wants a magic bullet. Like an injection they could give the stallion or something they could feed, but there are not very many things that actually work to fix the problems. Most products that you see advertised don’t have any research to back them up.” Stallion owners need to do a bit of homework and try to separate the facts from the hype.
Every stallion is a little different. It’s important
to work with a veterinarian who specializes in equine reproduction on a case by case basis to figure out what might help a certain stallion the most and to work through the individual problems. “One thing that can be done with a horse that has issues with motility would be to try the semen in different extenders or with different antibiotics in those extend- ers to see if that is what is impacting sperm motility,” says Sheerin.
“Another thing to try would be to centrifuge the semen. There are some cushion products available
to put into the bottom of the tube that you use for centrifuging. These enable you to spin the semen longer and harder while recovering more of the sperm
Heather Smith Thomas
64 SPEEDHORSE, March 2018
equine health